RU2236319C2 - Method for profiling thin-web shapes and apparatus for performing the same - Google Patents

Abstract

FIELD: plastic working of metals.

SUBSTANCE: method of profiling thin-web shapes of flat blank comprises steps of bending blank at successive transitions for providing necessary amount of metal on bent portions and further displacing metal in profiling direction at bending flanges; providing desired amount of metal by knurling (during first transition) cross corrugations having constant pitch along the whole width of blank and depth gradually lowering from maximum along width of profiled web until zero in both edges of bent portions of flat blank; displacing metal by expanding cross corrugations during further transitions and suppressing waviness of edges due to equalizing deformation and stress values along the whole cross section of profiled shape. Method is realized with use of apparatus including row of profiling stands arranged according to technological order and mutually joined by means of one kinematic circuit with common drive unit. Each profiling stand has two shafts arranged one over another and supporting profiling rolls. Ends of upper profiling rolls are mounted in sliding sleeves that may vertically move along guides of walls of stand housings. Profiling rolls of first profiling stand are cylindrical ones. Lower metallic profiling roll has constant -pitch riffles with triangular rounded cross section and height h equal to (3 - 5)So or less alternating with smooth segmental surfaces, where So - initial thickness of blank. Upper metallic profiling roll is cylindrical in zone of profiled web of shape; its cylindrical portion smoothly passes to cone in zone of bent flanges. Upper roll is faced along its whole length with elastic material whose thickness is minimum in cylindrical portions and increased in ends.

EFFECT: enlarged manufacturing possibilities of method and apparatus, enhanced quality of shape.

6 cl, 3 dwg, 1 ex

Description

The invention relates to the field of metal forming and can be used, in particular, in the manufacture of thin-walled profiles from sheet blanks by roll profiling for aerospace products and the construction industry. The invention is aimed at expanding technological capabilities and improving the quality of bent from a sheet of profiles.

A known method of profiling predominantly channel channels (see AS No. 1754267 of the USSR, IPC ⁵ B 21 D 5/06, publ. 08/15/92, bull. No. 30), which consists in bending profile elements along transitions with a technological bend of a part of each shelf profile width (0.25-0.45) b, where b is the width of the shelf, at an angle Δ α with subsequent straightening in the last two transitions.

The disadvantages of this analogue are:

profiling is carried out in nine transitions, which is cumbersome for thin-walled profiles, requires an increased amount of equipment;

technological hem often shelves is carried out at transitions from third to seventh, which complicates the equipment;

the strictly regulated width of the fold zone of the shelf, its straightening at the last two transitions also complicates the design of the rolls, and in other cases the quality of the profiles is not guaranteed, the waviness of the edges of the shelves is observed.

A known method of manufacturing bent profiles of rolled products (see AS No. 795620 USSR, IPC B 21 D 5/06, publ. 12.01.81, bull. No. 2), according to which in order to improve the quality of profiles by preventing their longitudinal twisting and deflection, when a molding force is applied from the side of the rolls and additional forces are applied to the profile perpendicular to its wall, additional forces are applied to the profile in the deformation zone simultaneously with the molding force.

The disadvantages of the method:

uncertainty of force to ensure quality profiles;

there is no guarantee in preventing longitudinal twisting due to additional efforts, since the deformation of the profile will be determined by the accuracy and nature of the impact of the applied molding force.

Closest to the technical nature of the claimed is the selected as a prototype "Method for the manufacture of bent profiles of hire" by as No. 1068199 USSR, IPC B 21 D 5/06, publ. 01/23/1984, bull. No. 3, according to which, in order to improve the profile quality by eliminating the undulation of the shelves in the manufacture of predominantly channels with a variable wall height, a temporary transverse corrugation with cross-sectional dimensions that are variable along its length is performed at successive bending along transitions at the place where the constant-width section joins with the narrowed section; in the section of the future profile wall and gradually decreasing in the sections of future shelves to zero at the edges, and then when folding the shelves the corrugations are straightened out with the crowding out metal TCA in the longitudinal direction.

The prototype and the claimed invention have the following similar essential features:

bending sequential in transitions;

ensuring the necessary supply of metal in bending areas;

its subsequent displacement in the direction of profiling when folding shelves.

The disadvantages of the prototype are:

uncertainty in the size and location of the transverse corrugation, which does not guarantee quality, because the formed stock of material must correspond to the geometry of the cross section of the profile, the thickness of the workpiece and the mechanical properties of the material;

it is not clear when and at which transition or transitions the transverse corrugation is carried out and how it is straightened during folding (gradually or at the last transition, etc.).

A device is known "Bending machine" (AS No. 48-8716 Japan, publ. March 16, 73, bull. "Inventions Abroad"), which includes shaped rolls, the molding surface of which in one is in the form of protrusions and in the other - grooves, the workpiece to be bent is fed into the gap between them. The gap is changed to match the original thickness of the workpiece.

The disadvantages of the analogue:

the machine performs longitudinal corrugations on the workpiece, and therefore the protrusions and depressions go perpendicular to the axis of the rolls;

the shape of the protrusions and depressions is uncertain, which does not guarantee the quality of the profiling of the workpiece with different material and thickness.

It is also known "Device for the manufacture of profiles" (see patent No. 2148455, IPC B 21 D 5/06, publ. BI No. 13, 05/10/2000), according to which profiles from sheet blanks are made in alternating forming and pulling working stands, each of which is included in one common kinematic chain associated with the drive. The working stand has two shafts located one above the other, on which roll forming rolls (rollers) are rigidly fixed. The upper shaft of each stand is located at the ends in slide sleeves having the ability to move vertically along the guide cheeks of the stand body.

The device is adopted as a prototype.

The prototype and the claimed invention have the following similar essential features:

contains a number of stands milling for transitions installed in the technological sequence;

profiling stands are connected by a single kinematic chain with a common drive;

each profiling stand has two shafts located one above the other, with profiling rolls mounted on them;

the ends of the upper profiling rolls are placed in slide sleeves having the ability to move vertically along the guide walls of the casing.

The prototype has the following disadvantages:

the complexity of the kinematic chain, consisting of a system of gears, including with additional external gearing, which increases power loss and reduces the efficiency of the device;

there is no certainty in eliminating waviness along the edges of the bent sections of a thin workpiece (S ₀ ≤ 1.0 mm), which does not guarantee the quality of the profiles.

The technical result is the expansion of technological capabilities and improving the quality of profiles.

To achieve a technical result, the claimed invention "A method for profiling thin-walled profiles and a device for its implementation" contains, in addition to the characteristics common with the prototype, the following distinguishing features:

according to the first claim, the necessary supply of material to improve the quality of the profiles (rigidity) and eliminate waviness along the edges is created by rolling the transverse corrugations at the first forming transition with a constant step over the entire width of the workpiece, with a depth decreasing gradually from the maximum width of the future profile wall to zero by both edges of the bent sections of the flat workpiece; the displacement of the metal reserve for the subsequent equalization of stresses and strains over the cross section (improving the quality of the profiles) is carried out by rolling the transverse corrugations at subsequent transitions, which eliminates the waviness.

According to the second claim, at the last transition, the thin-walled profile is calibrated, increasing its quality.

According to the third paragraph of the claims, profiling of thin-walled profiles of channel sections is carried out, which is the simplest one, since it reduces to bending of the end sections of a flat workpiece.

A device for profiling thin-walled profiles from flat blanks, in addition to the features common to the prototype, contains a number of stands profiling along the transitions installed in the technological sequence, connected by a single kinematic chain with a common drive; each profiling stand has two shafts located one above the other with profiling rolls mounted on them; the ends of the upper profiling rolls are placed in slide sleeves that are able to move vertically along the guide walls of the casing, has the following distinguishing features:

profiling rolls of the first profiling stand are cylindrical;

the lower profiling roll is made of metal with corrugations arranged with a constant pitch in the form of protrusions of a triangular rounded section;

corrugation height h≤ (3 ... 5) S ₀ , where S ₀ is the initial thickness of the workpiece, corrugations alternate with smooth segmented surfaces;

the upper profiling roll is made of metal, has a cylindrical shape in the future profile wall section, smoothly turning into a conical shape in the section of foldable shelves;

the upper profiling roll is lined along the entire length with an elastic material, the smallest of which is the smallest on the cylindrical part, increases towards the ends, so that the rigidity of the lining will reduce the height of the corrugations at the ends to zero.

The listed features provide the expansion of technological capabilities and quality profiles. The last profiling stand is made with a closed working caliber, has an increased rotation speed to create additional tensile forces, provides calibration of the outgoing profile, and corrects it by stretching, which improves the quality of the profile.

The most simple design of the proposed device will be in the manufacture of channel profiles.

Between the distinctive features of the claimed invention and the technical result there is the following causal relationship:

the creation of transverse corrugations on the workpiece provides the necessary supply of material, on the rolling of which in the profiling direction part of the material compensates for the unevenness of deformations along the width of the foldable shelves and the wall, and part of the material "flows" into the corner zones, which increases the rigidity of the profile, eliminates the edge waviness, and therefore, improves the quality of manufactured profiles;

the height of the corrugations of the lower roll of the first forming pair is up to 3.0 ... 5.0 of the thickness of the profiled material, the constancy of their pitch and alternation with smooth segmented surfaces eliminates the possibility of bending of the workpiece, which expands technological capabilities (different corrugation heights for different grades of materials and different pitch ) and improves the quality of profiles;

the facing of the upper roll with elastic material, its various thicknesses, make distributed deforming forces of various sizes along the workpiece width, due to which the corrugations get variable in depth cross-sectional shape, which also extends technological capabilities and improves the quality of profiles.

The set of essential features characterizing the essence of the invention can be repeatedly used in roll forming machines and mills, drawing and rolling plants in the manufacture of sheet-walled thin-walled wide-shelf profiles in mechanical engineering, the construction industry and the aerospace industry for a wide range of materials, including difficult to deform, in conditions cold deformation, which allows us to conclude that the invention meets the criterion of “industrial applicability".

Some distinctive features of the proposed technical solution are more or less known in the literature:

creation of transverse corrugations when profiling sheet blanks (ac. No. 1068199);

rolling transverse corrugations (ac. No. 068199);

the use of elastic deforming medium (polyurethane) is widely carried out in the blanking and stamping industry, etc.

According to the information available to the authors, the set of essential features characterizing the essence of the claimed invention is unknown from the prior art, which allows us to conclude that the invention meets the criterion of "novelty."

According to the authors, the essence of the claimed invention does not follow explicitly from the prior art for a specialist, since the above influence on the technical result is not revealed from it - a new property of the object: a set of features that distinguish the claimed invention from prototypes, which makes it possible to conclude its compliance with the criterion of "inventive step".

The invention is illustrated graphic materials. Figure 1 presents the profiling scheme with the creation of transverse corrugations and a top view of the roll device; in Fig 2 - section aa in Fig 1; in Fig.3 is a section bB in Fig.1 is the structural elements of the roll pair of the first transition.

The method is as follows.

A flat workpiece 1 with a thickness S ₀ ≤ 1.0 ... 2.0 mm, freely moving in the guides 2, is captured by the rotating rollers 3, 4 of the first forming working stand 5 (Fig. 1), where transverse corrugations are rolled on it across the entire width (corrugation) 6 of variable cross-sectional shape with a constant pitch t and depth gradually decreasing from h = h _max = const along the width of the future profile wall to h = 0 along both edges of the bent sections of the workpiece. In this case, the workpiece in the places of formation of the corrugations has practically no thinning, since the rolls 3, 4 are installed on the axial plane with some clearance and are freely drawn into it (Fig. 2). At subsequent transitions in roll pairs of stands 7, 8, etc. (driven or non-driven) in closed working calibers of the rolls, the corrugations are rolled out with equalization of tensile and stress strains over the entire cross section of the future profile due to the displacement of the material in the profiling direction with the elimination of the waviness of the edges of the resulting profile 9.

The method is carried out using the device (figure 1), consisting according to the second claim of the invention from a number of profiling stands 5, 7, 8, etc. (driven and non-driven) installed in the technological sequence, including rolls 3, 4, 10, 11, etc. with a profiled working surface. The roll pair of the working stand 5 has corrugations (knurling) over the entire width of the lower roll 4 of a triangular rounded shape in the form of protrusions 12. The height of the corrugations h = h _max ≤ (3.0 ... 5.0) S ₀ depending on the geometric characteristics of the transverse sections of bent elements and mechanical properties of the profiled workpiece. The corrugation pitch is constant. The protrusions alternate with smooth segmented surfaces 14 in order to ensure the required excess material to eliminate the corrugation of the profile along the edges. The lower roll 4 is a completely metal cylindrical shape. The upper roll 3 of metal has a cylindrical shape in the area of the future profile wall (Fig. 3), smoothly turning into a conical shape 15 in the area of foldable shelves. The roll is lined with elastic material 16 along the entire length. The lining of the roll 3, for example, with polyurethane of different thickness along the length of the roll, the smallest on the cylindrical part, the largest at the ends. The thickness of the elastic part depends on the grade of the material of the workpiece to be profiled, its thickness and the elastic properties of the cladding material. The outer lined surface of the roll 3 is cylindrical over the entire length. To adjust the workpiece thickness S _{0, the} upper roll 3 together with the shaft 17 (Fig. 1), the ends of which are enclosed in slide sleeves 18, can be moved vertically. The shafts of the working stands are placed in the walls of the device body; rolls with profiled working surfaces are mounted between the walls on them.

According to the third claim, the last (final) roll pair of the working stand 8 in the device is calibrating, made with a closed working caliber, has an increased profiling speed to create additional tensile force.

The device operates as follows. The rotation from the common drive through the transmission system is transmitted to the shafts of the profiling stands. The roll tape 1 from the feeding device, through the guides 2, is captured by the drive rolls 3, 4. The roll 3 compresses the thin workpiece 1 around the corrugations 4. Due to its cylindrical elastic surface, the workpiece is bent in the area of three corrugations with h = h _max only along the diametrical plane of the rolls. Then the corrugated workpiece is fed into a drive roll pair 7, rolls 10, 11 of which have a smooth working surface and provide partial bending of the workpiece on sections of future shelves and rolling the corrugations according to the shaping scheme.

Due to the different stiffness of the elastic cladding, the corrugations in non-bending sections of the workpiece receive the same section shape with a height of h = h _max ≤ (3.0 ... 5.0) S ₀ depending on the mechanical properties of the workpiece and gradually decreasing height to h = 0 along the edges where the greatest thickness of the elastic lining (the smallest rigidity), with the same pressure of the rolls on the workpiece.

The corrugations are rolled out in at least two roll pairs with a smooth working surface with a gradual folding of the shelves in the manufacture, for example, of a channel profile up to 90 ° in a calibrating roll pair 8, which, due to the increased rotation speed, creates an additional tensile force, which ensures equalization of deformations and stresses along the entire profile section.

Example. On bending and rolling machines of the GPS-300M model, drawing and rolling installation of the VPU-120 / 7.5 model, the proposed technical solutions were worked out when profiling workpieces S ₀ = 0.5 and 0.8 mm, 1.0 and 1.5 mm from sheet blanks of alloys D16AM, D16AT, OT4-1, various steels in the manufacture of rolls with corrugations of 2.0 and 4.0 mm. For facing the upper rolls of the first pairs used polyurethane brand SKU-7L and SP-7. Corrugation step through 20 S ₀ . The gap in the rolls of the first pair in the non-grooved sections Z to 0.5S ₀ . Metal thinning in the corrugation zone did not exceed 1.5 ... 2.5%. It was possible to eliminate the edge waviness in all cases of channel profiling by the dimensions of the wall and shelves 50 × 50 mm.

The claimed invention "A method of profiling thin-walled profiles and a device for its implementation" is of interest to the national economy, as it allows you to profile in the cold state sheet blanks with a thickness of up to 2.0 mm from a wide range of metals with an accuracy of profile parameters corresponding to 10-14 qualities. The combination of rolling and drawing processes eliminates not only the waviness of the edges, but also reduces springing, improves surface quality, and makes the metal structure fine-grained.

The claimed technical solution does not adversely affect the state of the environment.

Claims (6)

1. A method of profiling thin-walled profiles from flat billets, comprising bending sequentially along transitions with ensuring the necessary supply of metal in the bending sections and its subsequent displacement in the direction of profiling during folding of shelves, characterized in that the necessary supply of metal is created by rolling transverse corrugations at the first forming transition with constant step over the entire width of the workpiece with a depth that decreases gradually from the maximum width of the future profile wall to zero on both edges of the hem aemyh portions of the slab, and the displacement of the metal is rolled stock is carried on the transverse corrugation junctions with subsequent removal of waviness at the edges due to alignment deformations and stretching stresses along the entire cross section of the manufactured profile. 2. The method according to claim 1, characterized in that at the last transition the thin-walled profile is calibrated. 3. The method according to claim 1 or 2, characterized in that the profiling of thin-walled profiles of the channel section. 4. A device for profiling thin-walled profiles from flat billets, containing a number of cross-profiling stands installed in a technological sequence connected by a single kinematic chain with a common drive, each profiling stand has two shafts located one above the other, with profiling rolls mounted on them, the ends of the upper profiling rolls are placed in slide sleeves having the ability to move vertically along the guide walls of the casing, characterized in that the profiles uyuschie first shaping rolls stand are cylindrical, the lower profiling roll formed metal disposed with a constant pitch corrugations in the form of a rounded triangular shape projections h≤ sectional height (3 ... 5) S _0, alternating with smooth surfaces segment where S ₀ - the initial thickness of the blank, and the upper profiling roll is metallic, has a wall at the site of the future profile of a cylindrical shape, smoothly passes into a conical shape in the area to buckle shelves, and lined throughout Line resilient material whose thickness is smallest in the cylindrical portion and is increased at the ends. 5. The device according to claim 4, characterized in that the last profiling stand is calibrated with a closed working caliber and has an increased rotation speed to create additional tensile forces. 6. The device according to claim 4 or 5, characterized in that it is intended for profiling thin-walled profiles of channel sections.

Images